Collet attachment for lathes



A. PANzA Erm.

v COLLET ATTACHMENT FOR LTHES Aug. 1944.

Filed Ot. 28. 1942 Patented Aug. 1, 1944 Alimony Panza and William E. Panza, i i LosAngelesJ Calif.

VApplfuation otobezs, 1942, serial No.; 463,656

' Achims. (cl. 27s-#50) This invention relates to acollet chuck attachment.

More specifically speaking; the invention relates to acollet attachmentfor lathes which is operable to grip or release abar or other article extending through the headstock of the lathe'and being operated upon.k With our improved attachment upon releasing the grip on the Work the collet attachment is `permitted to rotate continuously, thereby avoiding the necessity ofstopping the rotation of the collet ychuck'to remove one piece of work and substitute another, or to adjust to a different position a piece of work which is being gripped by the rotating chuck.

- Among the objects of the invention are; l

To'improve upondevices .of the. above stated kind in regard to reducing the number of loperating parts, providing a more quickly operable lever controlled means for'grippingand releasing the Work, and also to improve upon prior structures in regard to simplicity, and durability of structure and ease of operation.

Another object of the invention is to provide improved means for attaching to lathesnow onv the market Without altering their structures, a

collet operating device for gripping and releasing the work without stopping the rotation of the chuck.

Yet another object of the inventionrelates to the provision, as a newarticle ci manufacture, of a resilient 'collet to take the place of ,a turret lathe headstock and peculiarly well adapted to be contracted to grip, and expanded to release, a piece of work. l

Other objects, advantages and features of invention Will hereinafter appear.

Referring to the accompanying drawing, which illustrates what is at present deemed to bea preferred embodiment of the invention,

Fig. 1 is a plan View of the structures which pertain to the invention, a conventional headstock and lathe spindle with which these are associated, being outlined'i'n broken lines. v

Fig. 2 is a hcrizontalsectionthe axis ofthe lathe lying 'i'n the plane of section.l

' Fig. 1 is on a somewhat smaller scale. than Fig. 2, andFig. 3 is on a still smaller scala Fig. 3 is a vertical sectionon-line 3--3 of Fig. 1. Y l

Referring in detail `to the drawing, onto a.` conventional tubular lathe headstockzspindle 5 carried by the headstock 6, is screwed aspindle attachment consisting of an internally @threaded `'annular member 1 having at its outer end a thick Vinternal annular vlip 8 Which 'is .rectangular in cross section, and an external peripheral flange 9,

the latter being Ilocated in an inwardly` spaced relation to the outer end of said annular member l. The lathe lspindle has an external peripheral flangeA 5a to' limit the onscrewing of the annular member 1.

yA work-gripping collet I0 is clamped axially against the outer end of the headstock spindle5 bymeans of the aforesaid annular member'l, said collet having a diametrically enlarged base I'I having around it an external angular recess I2 into which the rectangular lip 8 nts soas" not only to clamp the collet against the end of the lathe spindle but to con-center and stabilizefsaid collet against lateral deflection. At its outer end said collet has a forwardly tapered head I5' which is diametrically split at I6, the split extending inwardly throughout the greater portion of. the lengthof the collet. A circumferential, half roundv groove l'l surrounds the collet opposite to the inner end of itssplit I6, said groove being located at the inner end of the diametrically reduced tubular part I8 of the collet. ySaid groove Il reduces the thickness of the collet wall and thus adds to the springiness thereof. Different parts of the .axial passage of the collet vary in diameter, the part of said passage which leads through the head of the collet being of the least diameter.

An external clamping'sleeve 2B surroundsthe collet l0 and annular member 1. ASaid clamping sleeve 2U is forwardly tapered and furnishedat Aits'outer end with an internal bevel 2l which cooperates withthe tapered outer surface of "the 354head`f|5 of the collet. ASaid clamping sleeve 20 is of a rearwardly expanded, internally stepped character thus providing an internal angular an'- nular shoulder 2 lv and farther back an internally :threaded tubularV portion 22 into which screws 40 an externally threaded collar 23. Said collar 23vts loosely around the annula member or sleeve l and, as viewed in Fig. 2,' has a pair of diametrically opposite recesses 24 cu-t into itsY left end to receive a1 suitable wrench` The opposite or front end of said collar abuts Aagainst 'a stocky coil spring 25; which in'turn acts against the rear side of the flange 9 of the annular member 1, said spring therefore causing the internal bevel 2| of the `front part of -the clamping sleeve 218 `firmly to press against the beveled surface of the collet head I5 except whenA its pressure thereupon is relaxed by the means presently to be' described. The `workman can accurately gaugethe amountl of this pressureby .65 7screwing in the ring 23 thefproper distance. 'Ihe Alever.

When the cam `in Fig. 1 with its cam face 39 in contact with the `jaws is obviated.

threaded portion 22 of the member 20 is extended rearwardly a suicient distance to enable the workman to screw the collar into at least a flush relation to'said portion 20 before the spring 25 begins to be compressed, thus facilitating putting said collar into its operative position.

Around the sleeve portion 22 of the clamping member 2D is snugly fitted a steel bearing ring 26 the outer side of which abuts against an annular shoulder 21 provided therefor around said member 20, the opposite side of said bearing ring u z being engaged at diametrically opposite points by` the ball bearing structures 28 surrounding the circular heads 29 furnished with stub shafts 29a fixed to the yoke arms 3||` of the lever 3|. Said isA lever is mounted upon a bracket 32 having an angle-iron attaching arm 32a which, by means q ured to7^ of the usual headstock screws 33 is sec the frame of the lathe.

Said bracket 32 isshown made intwo pieces which are welded to'each other, its body vportion .34, aswell as its arm 32abeing of a rightangular character, and the aforesaid yoke-carrying lever vthe part thereof whichis nearest to the clamp- 1 To the outer part Vof said ing member` 20. bracket body isfpivoted a manually operable vcam lever 31 by means of a pivot bolt 38 which is located close to the cam faces 39 and 4l) of 'this lever 31' is positioned as shown main lever3| the parts are maintained in the position shown in Fig. 2 wherein the-internal bevel 2| of the clamping member 20 allows the split collet head |5 toexpand suilciently to release the rod or other work being operated upon; but when the cam lever is swung as indicated by the arrow adjacent thereto in Fig. 1 to a position .wherein its cam face 40 (nearest to its pivot) engages the lever 3|, the ball bearing structure carried by the yoke 3|) moves rearwardly toward .the left-a short distance, being caused to do so'by the action of the spring 25 upon the intervening structures, thus moving theclainping member 20 `rearwardly far enoughto contact the collet head I5 to the extent necessary to grip the work. Owing to the flat character of the cam faces'39 and 40. of thelever 3l and to the fact that these cam faces cooperate with a straight .edge or; 'face of the lever 3| while the spring impelledl lever 3| maintains a steady pressure upon the cam faces, the two levers are dependably maintained in their adjusted relation to each other Whichever of the two cam facesvof the cam lever contacts with the main lever 3|.

Without stopping the rotation of the lathe spindle the device may be rapidly operated both to release the hold of the collet upon the work and to renewits grip thereupon after the work has been readjusted or a new piece of work inserted. Also the necessity of resetting clutch In case a rod is being cut intor sections by the lathe to which the device is attached, such rod may extend axially into thespindle of the lathe for a considerable distance and be rapidly fed forward step by step to a cutting tool without stopping the rotation of the lathe.

It is only necessary to move the cam sleeve 20 3| is pivotally attached at about its mid-length v. vto the bracket body 34 by means of a pivot bolt other pieces of work of different diameters a number of collets will be provided each being of the same general design but varying in their size. It should be understood that the present disjclosure is for the rpurpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the ,subject matter claimed.

' What is claimed is:

1. In a collet attachment for lathes, a resilient collet having a tubular body and a diametrically vexpansible head which istapered away from said =body,' means for'securing said body to the outer :endportion of a lathe spindle in axial alinement therewith, a clamping sleeve mounted upon said Vsecuring means in a surrounding relation thereto said sleeve having an internally tapered poritionV which is in a surrounding contacting relation to the aforesaid tapered portion of said head, said sleevehaving a slight axial movement in relation to said collet, spring means carried by the vaforesaidsecuring means in a position tourge said sleeve in a direction to cause its internally tapered portion to maintain the collet in a contracted condition to grip work, means to move said sleeve in opposition to said spring, thereby ,toY allow said collet to expand and relax its grip .upon the work, said means for moving said sleeve including a main lever pivotally supported between its ends with one of its ends positioned lto yact upon said sleeve, and a manually operable cam lever positioned to act upon the opposite end portion of said main lever, said cam leverv having a plurality of flat cam faces which dependably -maintain it in various adjusted positions.

2. In a collet attachment for lathes, afresilvient collet having a tubular body and a diametrilcally expansible head which is tapered away from said body, means'for securing said body to the outer end portion of a lathe spindle in laxial Qalinement therewith, a clampingl sleeve mounted upon said securing means in a surrounding re- 'lation thereto, said sleeve having'an internally tapered portion which is in a surrounding contacting relation to the aforesaid tapered portion of said head, said sleeve having a slight axial movement in relation to said collet, said securing means being annular and having around it an external I'circumferential flange, a ring `loosely surrounding said securing means, said sleeve havingan internally threaded portion into 'which said ring-is screwed, a'compress'ion spring coiled aroundsaid securing means `in a position to urge-apart said flange thereof and said ring, Ythereby to urge saidsleevein a direction to cause its internally tapered portion to maintain the collet in a contracted condition to grip work, and means to move said ysleeve 'inopposition to said spring, Athereby to allow said-collet to expand `and relax its grip upon the Work. Y

3. In a collet attachment for lathes, a resilient Icollet having a tubular body and a diametrically J expansible headwhich is tapered away from said body, means for securing said body to the outer end portion of a lathe spindle in axial alinement therewith, a clamping sleeve mounted upon said securing means in a surrounding relation thereto, said sleeve having an internally tapered portion which is in a surrounding contacting relation to the aforesaid tapered portion of said head, said sleeve having a slight axial movement in relation to said collet, said securing means being annular and having around it an external circurnferential flange, means loosely surrounding and operatively connected to said securing means, yieldable means acting between the latter means and the flange of said securing means, thereby to urge said sleeve in a direction to cause its internally tapered portion to maintain the collet in a contracted condition to grip work, and means to move said sleeve in opposition to said yieldable means, thereby to allow said collet to expand and relax its grip upon the work.

4. In a collet attachment for lathes, a collet having a tubular body furnished at its outer end with an expansible and contractible head which is outwardly tapered, there being an external angular recess extending around the inner end portion of said body, thereby producing an annular flange around the inner end thereof, an annular member having an internally threaded portion to screw onto the headstock spindle of the lathe, said annular member having an internal annular lip along which extends an angular corner portion which fits into said angular recess and thereby clamps said collet against the outer end of the headstock spindle in axial alinement therewith and at the same time by lateral contact therewith stabilizes said collet against being deflected from said axial alinement, a clamping sleeve mounted upon said annular member in a surrounding relation thereto, said sleeve having an internally tapered portion which is in a surrounding contacting relation to the aforesaid tapered portion of said head, said sleeve having a slight axial movement in relation to said collet, spring means carried by the aforesaid securing means in a position to urge said sleeve in a direction to cause its internally tapered portion to maintain the collet in a contracted condition to grip Work, and means to move said sleeve in opposition to said spring, thereby to allow said collet to expand and relax its grip upon the work.

ANTHONY PANZA. WILLIAM E. PANZA. 

